The present invention relates to an apparatus for recovering grease from a grease separator. In particular, the present invention relates to a sensor operative for sensing the presence of a thickened layer of grease in a body of effluent.
It is known to pass the effluent from food processing facilities or other operations through devices for removing grease, to enable the grease to be kept out of a sewage system. Some such devices use a sensor for sensing the presence of a thickened layer of grease in the body of effluent in the device. The output of the sensor is then used to control pumping of grease from the device. An example of such a device is the automatic interceptor shown in U.S. Pat. No. 5,705,055, which shows a capacitance level switch located at a specific height in the device. The level switch provides an SPST switch closure to an electric controller to indicate the presence of a certain level of grease and the need to commence pumping of grease.
Some interceptor systems are manual, that is, do not have an automatically actuated pump. Thus, the grease level in the tank increases until it is manually removed. In manual systems, the level of grease contained in a tank can only be determined by physical inspection (i.e., the tank lid must be removed). Scheduled inspections may occur after the tank has already filled and grease has begun to flow into the sewer system, creating a significant problem. Therefore, there is an unmet need for a method of remotely determining the level of grease in the tank.
Another unmet need in the market arises from the fact that there is large variety of existing manual interceptor tank sizes and shapes available from multiple vendors. It would be impractical to design a custom level measurement system for each tank. In addition, not all manual interceptors are constructed of metal, and therefore not all are compatible with level measurement systems designed for metal tanks.
Thus, there is a need for a grease level measurement system with the following characteristics. The level measurement system must operate with the large majority of existing manual interceptor products. The level measurement system must be able to be retrofitted in the field on the large majority of installed manual interceptor products. The level measurement system would provide a local visual indication of the grease level and a local alarm when the grease interceptor tank requires servicing. The level measurement system would provide for remote monitoring of the grease level and a remote alarm when the grease interceptor tank requires servicing.
The present invention relates to apparatus for removing grease from an effluent stream containing grease and water. A separation tank defines a separation chamber. An effluent inlet connected with the separation tank permits flow of the effluent stream into the chamber to form a body of effluent in the separation chamber. A grease depth level sensor is used in determining the amount of grease in the body of effluent.
The interceptor may be queried remotely to check its status. In one embodiment, an output signal indicative of the amount of grease is transmitted over a telephone line to a telephone or computer or other remote station. Alternatively, the output signal is transmitted wirelessly to a remote receiver. The status is preferably also indicated locally with visual and/or audible signals.
The sensor is preferably a capacitive level sensor operative to sense the amount of water in the body of effluent thereby to determine the amount of grease in the body of effluent. The interceptor may include electric circuitry for effecting manual or automatic calibration of the grease depth level sensor. The sensor may be adapted to be retrofitted to an existing tank made from either metal or plastic.